The introduction of advanced non-destructive testing technology via a collaboration between Northrop Grumman, No. 33 Squadron and the Defence Aviation Safety Authority promises to reap significant benefits for KC-30A multi-role tanker transport refuelling hose maintenance.

The KC-30A is fitted with two refuelling pods for hose and drogue refuelling. Each pod has a 30m refuelling hose that has a steel braid covered in a neoprene outer sheath. Corrosion has been identified on the steel braid, making the hose unserviceable and in some cases unsafe.

Non-destructive inspection technicians (NDITECHs) from No. 33 Squadron and DASA recognised an opportunity for improving the maintenance and servicing of the aircraft’s refuelling hose through the introduction of electromagnetic eddy current array (ECA) testing.

The 30m-long air-to-air refuelling hose requires a frequent inspection to detect corrosion and general wear-and-tear. These inspections are critical to maintaining the longevity of the hose and minimising the risk of in-flight hose separations.

To minimise the potential of missed defects and reduce the time required to conduct inspections, Northrop Grumman and DASA worked with EddyFi, a Canadian-based company which specialises in ECA testing, to develop a customised inspection probe utilising rapid-prototyping production methods. The probe was then produced by EddyFi, and an inspection procedure developed by DASA. 

The probe scans the hose in minutes, searching for and pin-pointing corroded and damaged areas. It is millimetre-accurate and plugs into existing NDITECH computer equipment. 

Warrant Officer Greg Wilson, from DASA’s non-destructive testing and composite technology facility at RAAF Base Amberley, said this case study had influenced the design of similar technology for drogue hose maintenance applications around the world.

"The ECA method removes the need for and risk of relying on visual inspections, and enables the NDITECHs to extend the lifespan of the refuelling hose – thus reducing cost of ownership for the platform," Warrant Officer Wilson said.

"It’s a data-gathering tool that mitigates the failure rate of hoses and provides direct feedback to NDITECHs, engineering personnel and suppliers.

"The introduction of this equipment has led to advancement in new applications of this technology across the Defence and civilian aviation community."

Peter Booth, a No. 33 Squadron  NDITECH reserve corporal and DASA civilian contractor, said the magnetic field and electric pulses identified areas requiring further analysis.

"Safety is the primary benefit of such technology, as well as enhanced quality control," Corporal Booth said.

"We can locate corrosion early, be better informed with the correct data, and improve our management of it.
“This is just the start – we are always looking at future uses for ECA in partnership with uniformed, civilian and contractor personnel, to achieve today’s fifth-generation capability outcomes."